I’ve come to Melbourne’s Federation Square this Sunday afternoon searching for the followers of a man who had called himself Dr Hopeful.

If that nom de plume makes Ludwik Lejzer Zamenhof sound like the protagonist of an old-timey science-fiction movie, the comparison’s not altogether inappropriate. Zamenhof was the creator of Esperanto, a constructed language intended to unite nations and foster international harmony. The project he outlined in 1887 under the pen-name “Doktoro Esperanto” (“one who hopes”) today seems like a quintessential piece of retro-futurism, a linguistic artefact from a millennium that never quite dawned.

Yet there are still Esperantists in Melbourne – and this is where they meet.

The table at Beer DeLuxe isn’t hard to find, since most of the Melbourne Esperanto Association members are wearing necklaces adorned with the slightly futuristic Esperanto symbol: a green star on a white background. I’d expected them to be older, and, for the most part, they are: a small group of men and women, many near retirement age.

Joanne Johns, however, is different. She’s in her early 30s and looks much younger, with a pierced nose and vaguely punky hair. She works in IT, and she and her husband have been Esperantists since 2013. She came to it via Red Dwarf, the cult TV comedy about dysfunctional space travellers.

“One of the main characters is trying to learn Esperanto,” she says, “and the joke is he’s so stupid he can’t manage. When I watched it, I didn’t really get that Esperanto was something outside the show. One day I saw the word again in an article about something else. I looked it up and found out that it was a real language and thought it was a great idea.”

The Fed Square gatherings were her initiative, intended to attract a more youthful cohort than the one that attends the association’s regular Monday night classes nearby.

Constructed languages, or conlangs, have a long and fascinating history. According to Arika Okrent’s terrific book In the Land of Invented Languages, the earliest documented example is the mysterious Lingua Ignota, created by the 12th-century German mystic Hildegard von Bingen for purposes that remain entirely unclear.

Most conlangs seek to undo the curse of Genesis 11:1–9, in which, to frustrate the builders of the Tower of Babel, a jealous God decided to “confound the language of all the earth”. Language invention, says Okrent, became something of an intellectual fad in the 17th century, as scientists sought to spread their discoveries across nations. In the introduction to his original 1852 thesaurus, Dr Roget hoped that his linguistic classifications would contribute to “that splendid aspiration of philanthropists – the establishment of a Universal Language”.

LL Zamenhof was born in Poland to a Lithuanian Jewish family in 1859, a time when Tsarist oppression meant that persecuted minority groups in the Russian Empire necessarily thought a lot about language and culture.

“I was brought up to be an idealist,” he later explained. “I was taught that all men were brothers while at the same time everything I saw in the street made me feel that men as such did not exist: only Russians, Poles, Germans, Jews and so forth.”

In some ways, Zamenhof’s solution – Esperanto – was less ambitious than other conlangs. He did not try to reshape human thought; he did not replace letters with combinatorial symbols. Instead, he emphasised simplicity.

In Esperanto, each letter is pronounced. All singular nouns end in “o”; plurals are always made with the addition of “j”; adjectives end in “a”. Everything’s regular; everything’s consistent.

Johns tells me that after three months of learning Esperanto she could understand conversations; after six, she could engage in them.

“Today,” she says, “I’m very fluent.”

Esperanto does, however, feature a bunch of non-standard characters, which makes the written form look slightly forbidding. The Melbourne association has a card that includes the following sample: “Hey, there’s a dog! Do you like dogs? I have two big dogs.” In Esperanto, that already rather peculiar dialogue becomes “Jen, hundo! u vi atas hundojn? Mi havas du grandajn hundojn.”

Of course, once you start linguistic tinkering, it’s difficult to stop, and communities formed around invented languages have a propensity to split acrimoniously. Early on, Zamenhof lost a chunk of followers after some adherents suggested Esperanto could be improved (by, say, removing its accented letters); the dissidents duly announced their own conlang, Ido.

Despite that schism, the language made great strides through the first decades of the 20th century. Enthusiasts even created, in 1908, the short-lived state of Amikejo, an Esperanto-speaking territory located between the Netherlands and Prussia.

Not surprisingly, Esperanto was loathed by both Stalin (who saw it as a tool for spies) and Hitler (who denounced it in Mein Kampf as the language of Jewish conspiracy).

Zamenhof, whose children would later die in the Holocaust, distanced himself from an early enthusiasm for Zionism on a characteristically idealistic basis. “Despite the heartbreaking sufferings of my people,” he said, “I do not want to link myself with Hebrew nationalism, but I want to work only for absolute human justice. I am profoundly convinced that this way I will bring much more good to my unfortunate people than through the goals of nationalism.”

Yet the revival of modern Hebrew highlighted the importance of the nation-state in fostering culture and language, an obvious problem for a conlang aiming to transcend nationality. After World War Two, the hopes of Fabians and other progressives for a benevolent world-government faded – and, with them, the prospects for a language that such a government might use.

The Melbourne Esperanto Association (one of more than a dozen such clubs around Australia) dates from 1905. One of the early Victorian Esperantists was the country schoolmaster Henry Maynard Lanyon, grandfather of historian Geoffrey Blainey. As an early history by the Esperantist Ivan Maddern boasts, Lanyon was “one of the first to suggest national superannuation, and also the idea of a league of nations, even writing to President Wilson of the USA two years before the President himself proposed the idea in 1919”.

It’s an image – the rural teacher confidently mailing the president with a few helpful suggestions – that perfectly captures the genial optimism of the movement.

Johns explains that the local club still attracts a particular type of enthusiast.

“You have to be a certain kind of person to learn a language like this. Sort of nerdy, I guess. Interested in languages and peace. There are a lot of vegetarians who speak Esperanto; in Australia there’s quite a few of us who are in the IT field.”

Today, figures for international Esperanto usage vary wildly. The Melbourne association flyer claims six million speakers; other sources put the number as low as 100,000. But if you’re travelling abroad, there’s no doubt you’ll get further with English than with Esperanto.

Which is not quite to say that the language serves no purpose.

Johns tells me she is looking forward to this month’s historic 100th World Congress of Esperanto in Lille, France.

“Before you go overseas,” she says, “you can get in touch with the local associations where you plan to travel. Sometimes you get put up for free; you can stay in the homes of Esperantists.”

For Johns, Esperanto works not because it is universal but because it is exclusive. Rather than a global language, it’s a niche one, serving an international subculture of the like-minded.

The future sought by Dr Hopeful – a world free from war and national rivalries – might seem further away than ever. When I left Federation Square, however, the men and women of the Melbourne club were still happily conversing in the tongue invented in the late 1870s by this Yiddish-speaking Pole. In his failure, he’d achieved a paradoxical success.

I’ve come to Melbourne’s Federation Square this Sunday afternoon searching for the followers of a man who had called himself Dr Hopeful.

If that nom de plume makes Ludwik Lejzer Zamenhof sound like the protagonist of an old-timey science-fiction movie, the comparison’s not altogether inappropriate. Zamenhof was the creator of Esperanto, a constructed language intended to unite nations and foster international harmony. The project he outlined in 1887 under the pen-name “Doktoro Esperanto” (“one who hopes”) today seems like a quintessential piece of retro-futurism, a linguistic artefact from a millennium that never quite dawned.

Yet there are still Esperantists in Melbourne – and this is where they meet.

The table at Beer DeLuxe isn’t hard to find, since most of the Melbourne Esperanto Association members are wearing necklaces adorned with the slightly...